The presented invention relates to a retrofit and direct replacement of conventional fluorescent lighting tubes with light emitting diode (LED) lighting devices for usage in vehicles, including mass-transit vehicles such as buses, trains, subway trains, also for lighting watercrafts, aircrafts, signage, or buildings using LEDs.
For many years the lighting of interiors of vehicles, aircraft, buildings, signage, and watercraft, and more recently the lighting of exteriors of vehicles, and signage have use the cold cathode lamp; more commonly known as the fluorescent lamp or a fluorescent system. The fluorescent lamp however has limitations on its capabilities and usages. The fluorescent lamp has disadvantages to the consumer. The disadvantages of the fluorescent lamp are the short life, easily broken, low durability, high costs of replacement, high costs of specialty lights, limited color selection, electromagnetic interference (EMI) which may be harmful to other electronic equipment. The manufacturing of fluorescent lamps and debris from replaced lamps have a high environmental risks, as the chemicals inside of a fluorescent lamp are toxic. Also the flicker effect of dying or improperly installed fluorescent lamps may be extremely harmful to individuals with certain medical conditions. The constant inconsistency of fluorescent lighting colors is often a complaint of consumers who have to replace lamps on a regular basis. A fluorescent system cannot be used effectively in extreme low or high ambient temperatures.
To attempt to avoid difficulties with fluorescent lighting, proposals have been made to use LEDs as replacements for fluorescent lighting, as for example described in U.S. Pat. No. 6,860,628 issued Mar. 1, 2005 and U.S. Pat. No. 6,583,550 issued Jun. 24, 2003. While these devices do provide some of the advantages of LEDs, there remains a need for lighting systems that can supply sufficient illumination to meet lighting requirements in vehicles, including mass-transit vehicles such as buses, trains, subway trains, also for lighting watercrafts, aircrafts, buildings and signage without excessive heat build up, while reducing the amount of lamps, wiring, ballasts, power consumption and maintenance that fluorescent systems require.